The first deep reflection seismic profile was acquired across the Teisseyre-Tornquist Zone (TTZ), a major European suture zone, southeast of the Avalonia-Baltica collision zone, portraying different tectonic deformation styles (thick- versus thin-skinned) and Phanerozoic crustal accretion episodes over a relatively short distance (240 km). The overall crustal structure preserves image of the Neoproterozoic passive margin setting but with a significant overprint of the repetitive tectonic convergence (Cadomian to Alpine) acting at the Baltica margin. In contrast to the Avalonia-Baltica collision zone, here the polygenetic crustal accretion occurring at the cratonic margin was ultimately shaped by significant strike-slip faulting. TTZ is imaged as a narrow (10–15 km) transform zone separating the thinned East European cratonic crust from the Małopolska Block.